Indeed, I can think of three campaigns - without trying really hard - in which the GM obliterated the family and community ties I'd created for a character, often within the first few games. It was just the game kickoff in the Call of Cthulu game, of course, but in the other two*, it seemed to be purposefully to cut the PC(s) loose from a prior life before setting them off on the campaign voyage.
So how to run a campaign based around a tightly-knit community?
Conflict in a Community
The first answer is a cop-out. Make the community mobile. Whether we're talking about a ship's crew (sea ship or space ship), a gypsy band, a crowd of carnies, or a military or mercenary unit, there are plenty of medium to largish groups that wander around the landscape, doing stuff and having adventures.
If the community is not mobile, the first question that comes to mind is, "Where are the cops?" The reaction of most people to violent conflict (a staple of most RPGs) is to call the law. Getting around this suggests several different avenues:
- Make conflict come from something not illegal. You know all those soap operas and teen high school dramas? They focus on love, hate, revenge, pride and prestige, and the writers don't like the cops any more than GMs do.
- Make the PCs the Law (or the Organized Criminal Underground). If they don't want to be cops or guardsmen or Space Patrol, this isn't a good answer.
- Make the Law corrupt, stupid, or inaccessible. Maybe the PCs are part of a frontier town, a post-apocalyptic settlement, a remote medieval village in an enchanted forest, or some other place where folks have to make and enforce their own standards. Or the campaign is about occult mysteries that the regular law officers simply dismiss or otherwise get wrong. Or the cops are so corrupt that there's no hope of justice there.
Small towns lend themselves well to Scary Threats from Outside, with some character-centric interpersonal conflict inside the town as well. Big cities can serve as campaign settings with ease; travel through them can bring all kinds of interesting adventures to the stationary. Games that center on the nobility and their politics and plots would do well here; they have conflict without being bloody and they work best with a recurring cast of characters, all of whom are trying to score favors with each other.
Your PCs need to be on board for this, since it's rather different from most RPGs.
Although it strongly lends itself to character-driven campaigning, you can run other styles. In a plot-driven campaign, the GM will still be inventing hordes of NPCs, most of whom will be met once and then never again, as the PCs wander across the campaign world. Now the GM can still invent a horde of NPCs, but they all live in one area and the GM can get some reuse out of them. Instead of a random innkeeper begging the PCs to help him find his lost son, it's Renyard from the Two Flagons who's asking his customers and friends to help find his son, because that bastard Captain Jenkins insists the boy probably just left to find work and it's no affair of his.
A setting-based campaign can really shine here, if the GM spends time and attention on the different neighborhoods and institutions within the city or town. You don't have to go gallivanting across the globe to meet many imaginative locales.
I would not recommend a huge infodump on the players, though, just as you wouldn't infodump for a campaign with a larger geographic focus. Ask them to help you define a few NPCs and neighborhood institutions, and stick with those for the first game. As you go on, add detail and expand outward.
Regardless of your GMing style, part of the point of a game like this is to allow for the role-play of the interpersonal relationships that go into a really rooted, well-developed character. Even if your NPCs work in service to the plot, make sure the PCs have time to interact with the NPCs in colorful and interesting ways. It doesn't have to be extensive or time-consuming; I'm thinking back to the old Spider-Man cartoon where Aunt May usually had a few lines to say to Peter as he was heading out the door. We didn't actually see Peter eat an entire Sunday dinner with her, but we saw him helping her clear the table, which implied a lot more.
*The other two uprooted PCs were Lillian Purnell, along with all of the other PCs in hueffmea's Rifts game, was about to be sent to the salt mines on trumped-up charges, so the PCs escaped into the wilderness. Dr. Corker O'Shea lost her apartment, her job, and her father-figure advisor in a single 7th Sea game run by giddysinger; it would be many months before he finished the job by offing her best friend.